Heat pump

ABSTRACT

A heat pipe provided with an outdoor unit having a compressor and an outdoor heat exchanger, a plurality of indoor units provided to be driven at a cooling mode or a heating mode. an indoor unit mode control unit to control the each of the plurality of indoor units to be driven at a cooling mode or a heating mode. and a flow path conversion apparatus connected to a first refrigerant pipe and a second refrigerant pipe connected from the outdoor unit, connected to a high pressure gas pipe and a low pressure gas pipe connected to the indoor unit mode controlling unit, and configured to change the flow path of a refrigerant by selectively connect all or some of the first refrigerant pipe, the second refrigerant pipe, the high pressure gas pipe, and the low pressure gas pipe according to the mode at which the indoor units are driven.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of the Korean Patent Application No. 10-2014-0155573, filed on Nov. 10, 2014, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.

BACKGROUND

1. Field

Embodiments of the present disclosure relate to a heat pump, and more particularly, a heat pump provided with a plurality of indoor units while the each of the plurality of indoor units may be driven for heating or cooling.

2. Description of the Related Art

A heat pump is configured to connect a plurality of indoor units and at least one outdoor unit by use of a single pipe system, and both a heating and a cooling are provided. The heat pump is an apparatus configured to transport the heat proceeding from a higher place to a lower place toward an opposite direction by means of absorbing low-temperature heat and pulling up heat by use of high temperature. The heat pump is configured to perform an air-to-air and an air-to-water by use of the heat generated and collected during a circulation process of compression, condensation, and evaporation of a refrigerant.

In general, the heat pump is provided such that the connected plurality of indoor units is driven at an identical driving mode. In the case as such, users may not able to adjust the driving mode of the each of the plurality of indoor units even when the plurality of indoor units is installed at separate spaces. Accordingly, manufacturers, in order for the each of the plurality of indoor units to be provided with a separate driving mode, are needed to develop an air conditioner having a separate heat recovery cycle, other than a heat pump cycle, capable of simultaneously perform a cooling and a heating.

SUMMARY

Therefore, it is an aspect of the present disclosure to provide a heat pump provided such that the each of a plurality of indoor units is driven at a heating mode or a cooling mode.

It is another aspect of the present disclosure to provide a heat pump having a flow path conversion apparatus configured to change the flow path of a refrigerant being moved to an indoor unit or an outdoor unit.

Additional aspects of the disclosure will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the disclosure.

In accordance with one aspect of the present disclosure, a heat pump may include an outdoor unit having a compressor and an outdoor heat exchanger; a plurality of indoor units provided to be driven at a cooling mode or a heating mode; an indoor unit mode control unit configured to control the each of the plurality of indoor units to be driven at a cooling mode or a heating mode; and a flow path conversion apparatus connected to a first refrigerant pipe and a second refrigerant pipe connected from the outdoor unit, connected to a high pressure gas pipe and a low pressure gas pipe connected to the indoor unit mode controlling unit, and configured to change the flow path of a refrigerant by selectively connect all or some of the first refrigerant pipe, the second refrigerant pipe, the high pressure gas pipe, and the low pressure gas pipe according to the mode at which the indoor units are driven.

The outdoor unit may further include a first flow path conversion valve connected to the compressor, the first refrigerant pipe, and the second refrigerant pipe, and configured to selectively connect at least some of the compressor, the first refrigerant pipe, and the second refrigerant pipe.

The outdoor unit may further include an accumulator connected to the compressor, and a circulation pipe configured to sequentially connect the first flow path conversion valve, the accumulator, and the compressor.

A third refrigerant pipe configured to sequentially connect the first refrigerant pipe, the outdoor heat exchanger, and the indoor unit mode control unit may be further included.

The flow path conversion apparatus may include a second flow path conversion valve connected to the each of the first refrigerant pipe, the high pressure gas pipe, and the low pressure gas pipe, and configured to connect some of the first refrigerant pipe, the high pressure gas pipe and the low pressure gas pipe; a first valve installed at a second refrigerant pipe configured to connect the first flow path conversion valve and the high pressure gas pipe; and a second valve installed at a connecting pipe connecting the second refrigerant pipe and the low pressure gas pipe.

The connecting pipe may be connected in between the first valve and the first flow path conversion valve at the second refrigerant pipe.

The flow path conversion apparatus may further include a control apparatus configured to control the first flow path conversion valve, the first valve, and the second valve, and the control apparatus, in a case when the plurality of indoor units is altogether driven at a cooling mode, is provided to control the first flow path conversion valve to connect the compressor and the second refrigerant pipe and to connect the circulation pipe to the first refrigerant pipe, and the second flow path conversion valve to connect the second refrigerant pipe and the low pressure gas pipe.

The control apparatus, in a case when the plurality of indoor units is driven at a cooling mode altogether, is capable of controlling the first valve and the second valve to be closed altogether.

The flow path conversion apparatus may further include a control apparatus configured to control the first flow path conversion valve, the first valve, and the second valve, and the control apparatus, in a case when the plurality of indoor units is altogether driven at a heating mode, is provided to control the first flow path conversion valve to connect the compressor and the first refrigerant pipe and to connect the circulation pipe to the second refrigerant pipe are connected to each other, and the second flow path conversion valve to connect the first refrigerant pipe and the high pressure gas pipe.

The control apparatus, in a case when the plurality of indoor units is driven at a heating mode altogether, is capable of controlling the first valve and the second valve to be closed altogether.

The flow path conversion apparatus may further include a control apparatus configured to control the first flow path conversion valve, the first valve, and the second valve, and the control apparatus, in a case when the each of the plurality of indoor units is driven at a heating mode and a cooling mode and when the number of the indoor units driven at the cooling mode is greater than the number of the indoor units driven at the heating mode, is provided to control the first flow path conversion valve to connect the compressor and the second refrigerant pipe and to connect the circulation pipe to the first refrigerant pipe, and the second flow path conversion valve to connect the first refrigerant pipe and the low pressure gas pipe.

The control apparatus, in a case when the each of the plurality of indoor units is driven at a heating mode and a cooling mode and when the number of the indoor units driven at the cooling mode is greater than the number of the indoor units driven at the heating mode, is provided to control the first valve to be open and the second valve to be closed.

The flow path conversion apparatus may further include a control apparatus configured to control the first flow path conversion valve, the first valve, and the second valve, and the control apparatus, in a case when the each of the plurality of indoor units is driven at a heating mode and a cooling mode and when the number of the indoor units driven at the heating mode is greater than the number of the indoor units driven at the cooling mode, is provided to control the first flow path conversion valve to connect the compressor and the first refrigerant pipe and to connect the circulation pipe to the second refrigerant pipe, and the second flow path conversion valve to connect the first refrigerant pipe and the high pressure gas pipe.

The control apparatus, in a case when the each of the plurality of indoor units is driven at a heating mode and a cooling mode and when the number of the indoor units driven at the heating mode is greater than the number of the indoor units driven at the cooling mode, is provided to control the first valve to be closed and the second valve to be open.

The first flow path conversion valve and the second flow path conversion valve may be provided in a form of a 4-way valve.

In accordance with the embodiments of the present disclosure, each of a plurality of indoor units of a heat pump may be driven at a heating mode or a cooling mode.

The each of the plurality of indoor units of the heat pump may be driven at a heating mode or a cooling mode as a flow path conversion apparatus configured to change the flow path of a refrigerant being moved to the indoor units or to an outdoor unit is provided to change the flow path of the refrigerant being moved to the indoor units or the flow path of the refrigerant being moved to the outdoor unit.

The each of the plurality of indoor units of the heat pump may be driven at a heating mode or a cooling mode by installing the flow path conversion apparatus configured to change the flow path of a refrigerant being moved to the indoor units or to an outdoor unit at a conventional heat pumping apparatus.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects of the disclosure will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a drawing illustrating a heat pump according to one embodiment of the present disclosure;

FIG. 2 is a drawing illustrating a refrigerant cycle of the heat pump illustrated on FIG. 1;

FIG. 3 is a drawing showing a circulation of a refrigerant in a case when a plurality of indoor units of the heat pump illustrated on FIG. 2 is altogether at a cooling mode;

FIG. 4 is a drawing showing a circulation of a refrigerant in a case when a plurality of indoor units of the heat pump illustrated on FIG. 2 is altogether at a heating mode;

FIG. 5 is a drawing showing a circulation of a refrigerant in a case when a plurality of indoor units of the heat pump illustrated on FIG. 2 is at a main cooling mode;

FIG. 6 is a drawing showing a circulation of a refrigerant in a case when a plurality of indoor units of the heat pump illustrated on FIG. 2 is at a main heating mode;

FIG. 7 is a drawing showing the motions of an outdoor unit and a flow path conversion apparatus according to time in a case when the heat pump of FIG. 2 is driven at a cooling mode or a main cooling mode in a halted state;

FIG. 8 is a drawing showing the motions of the outdoor unit and the flow path conversion apparatus according to time in a case when the heat pump of FIG. 2 is driven at a heating mode or a main heating mode in a halted state;

FIG. 9 is a drawing showing the motions of the outdoor unit and the flow path conversion apparatus according to time in a case when the heat pump of FIG. 2 is driven at a heating mode or at a main heating mode during a cooling mode or a main cooling mode; and

FIG. 10 is a drawing showing the motions of the outdoor unit and the flow path conversion apparatus according to time in a case when the heat pump of FIG. 2 is driven at a cooling mode or at a main cooling mode during a heating mode or a main heating mode.

DETAILED DESCRIPTION

Reference will now be made in detail to the embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout.

FIG. 1 is a drawing illustrating a heat pump according to one embodiment of the present disclosure, and FIG. 2 is a drawing illustrating a refrigerant cycle of the heat pump illustrated on FIG. 1.

As illustrated on FIG. 1 and FIG. 2, a heat pump 1 according to one embodiment may include at least one outdoor unit 10, a plurality of indoor units 20, an indoor unit mode control unit 30, and a flow path conversion apparatus 40. The heat pump 1 may be connected to the each of the at least one outdoor unit 10, the plurality of indoor units 20, the indoor unit mode control unit 30, and the flow path conversion apparatus 40 by use of a plurality of pipes provided as to have a refrigerant moved.

The outdoor unit 10 may be provided in a single unit thereof or in a plurality of units thereof. On FIG. 1, for the convenience of descriptions, one unit of the outdoor unit 10 is illustrated, while the outdoor unit 10 may be provided in a plurality of units thereof, differently from FIG. 1.

The outdoor unit 10 may include a compressor 11 and an outdoor heat exchanger 12.

The compressor 11 may be installed at an inside of the outdoor unit 10. The compressor 11 may compress a refrigerant at high pressure state. The compressor 11 may compress a refrigerant into a state of gas at high pressure. The gas compressed into a state of high pressure gas may be moved to a certain one of the outdoor heat exchanger 12, the indoor unit mode control unit 30, and the flow path conversion apparatus 40 through the plurality of pipes.

The outdoor heat exchanger 12 may be installed at an inside of the outdoor unit 10. The outdoor heat exchanger 12 may be driven, according to the driving mode of the heat pump 1, as an evaporator configured to evaporate the refrigerant in a liquid state. In detail, the outdoor heat exchanger 12 may perform a role as an evaporator in a case when the indoor units 20 are driven at a heating mode.

Differently from the above, the outdoor heat exchanger 12 may be driven, according to the driving mode of the heat pump 1, as a condenser configured to condense the refrigerant in a gas state. In detail, the outdoor heat exchange 12 may perform a role as a condenser in a case when the indoor units 20 are driven at a cooling mode.

The outdoor unit 10 may further include a first flow path conversion valve 15, a first refrigerant pipe 16, a second refrigerant pipe 17, and a third refrigerant pipe 18.

The first flow path conversion valve 15 may be connected to the compressor 11. The first flow path conversion valve 15, according to the driving mode of the indoor units, may move the refrigerant in a gas state and compressed at high pressure to a certain one of the outdoor heat exchanger 12, the indoor unit mode control unit 30, and the flow path conversion apparatus 40.

The first flow path conversion valve 15 may be connected to the first refrigerant pipe 16, the second refrigerant pipe 17, and the third refrigerant pipe 18. The first flow path conversion valve 15 may be provided in a form of a 4-way valve.

The first refrigerant pipe 16 may connect the outdoor unit 10 and the flow path conversion apparatus 40. The first refrigerant pipe 16 may connect the first flow path conversion valve 15 and a second flow path conversion apparatus 41 of the flow path conversion apparatus 40, which is to be described later. The first refrigerant pipe 16 may be provided as a flow path through which the refrigerant in a gas state compressed at high pressure at the compressor 11 is moved to the flow path conversion apparatus 40. In addition, the first refrigerant pipe 16 may be provided as a flow path through which the refrigerant in a gas state at low pressure is moved from the flow path conversion apparatus 40 to the outdoor unit 10.

The second refrigerant pipe 17 may connect the outdoor unit 10 and the flow path conversion apparatus 40. The second refrigerant pipe 17 may connect the first flow path conversion valve 15 and a high pressure gas pipe 48 of the flow path conversion apparatus 40, which is to be described later. The second refrigerant pipe 17 may be provided as a flow path through which the refrigerant in a gas state compressed at high pressure at the compressor 11 is moved to the high pressure gas pipe 48 of the flow path conversion apparatus 40. In addition, the second refrigerant pipe 17 may be provided as a flow path through which the refrigerant in a gas state at low pressure is moved from the flow path conversion apparatus 40 to the outdoor unit 10.

The third refrigerant pipe 18 may connect the outdoor unit 10 and the indoor unit mode control unit 30. The third refrigerant pipe 18 may connect the first flow path conversion valve 15 and the indoor unit mode control unit 30. The third refrigerant pipe 18 may sequentially connect the second refrigerant pipe 17, the outdoor heat exchanger 12, and the indoor unit mode control unit 30.

The outdoor heat exchanger 12 may be disposed in between the first flow path conversion valve 15 and the indoor unit mode control unit 30, and the refrigerant being moved through the third refrigerant pipe 18 may be moved while condensed or evaporated in the process of passing through the outdoor heat exchanger 12.

The third refrigerant pipe 18 may be provided as a flow path through which the refrigerant liquefied while passing through the outdoor heat exchanger 12 is moved from the outdoor unit 10 to the indoor unit mode control unit 30. Differently from the above, the third refrigerant pipe 18 may be provided as a flow path through which the refrigerant in a gas state at low pressure being moved from the indoor unit mode control unit 30 is moved to the outdoor heat exchanger 12. The third refrigerant pipe 18 may be provided as a flow path through which the refrigerant moved from the indoor unit mode control unit 30 and liquefied at the outdoor heat exchanger 12 is being moved to the first flow path conversion valve 15.

The outdoor unit 10 may further include an accumulator 13 and a circulation pipe 19.

The accumulator 13 may be structured to be connected to the compressor 11 and the first flow path conversion valve 15. The accumulator 13 may be provided as to be connected to the compressor 11 and the first flow path conversion valve 15 through the circulation pipe 19.

The indoor unit 20 may be provided in a plurality of units thereof. On FIG. 1, for the convenience of descriptions, the indoor unit 20 is illustrated to have a first indoor unit 21, a second indoor unit 22, and a third indoor unit 23. However, differently from the above, the indoor unit 20 may include more than three units of the indoor units 20.

The each of the plurality of indoor units 20 may be driven at a cooling mode or a heating mode. The plurality of indoor units 20 altogether may be driven at a cooling mode or a heating mode. In addition, the plurality of indoor units 20 may be provided such that some of the plurality of indoor units 20 is driven at a cooling mode, while the remaining of the plurality of indoor units 20 is driven at a heating mode. For the above, the each of the plurality of indoor units 20 may be connected to the indoor unit mode control unit 30. In detail, the first indoor unit 21 may be provided to be connected to the indoor unit mode control unit 30 through first indoor unit connecting pipes 21 a and 21 b, the second indoor unit 22 may be provided to be connected to the indoor unit mode control unit 30 through second indoor unit connecting pipes 22 a and 22 b, and the third indoor unit 23 may be provided to be connected to the indoor unit mode control unit 30 through third indoor unit connecting pipes 23 a and 23 b.

The each of the plurality of indoor units 20 may be provided with an indoor heat exchanger (not shown) and an expansion valve (not shown). The indoor heat exchanger may be driven as a condenser or as an evaporator according to the mode of the indoor unit 20. In detail, the indoor heat exchanger may perform a role as a condenser when the indoor unit 20 is driven at a heating mode. In addition, the indoor heat exchanger may perform a role as an evaporator when the indoor unit 20 is driven at a cooling mode.

The indoor unit mode control unit 30 may be disposed in between the outdoor unit 10 and the indoor units 20. The indoor unit mode control unit 30 may move the refrigerant in a gas state at a high pressure and the refrigerant in a liquefied state that are moved from the at least one outdoor unit 10 to the each of the indoor units 20 according to the driving modes of the plurality of indoor units 20. In addition, the indoor unit mode control unit 30 may move the refrigerant in a gas state at a low pressure and the refrigerant in a liquefied state that are moved from the plurality of indoor units 20 to the outdoor unit 10.

The indoor unit mode control unit 30 may be connected to the high pressure gas pipe 48, a low pressure gas pipe 49, and the third refrigerant pipe 18. The indoor unit mode control unit 30 may be provided such that a refrigerant may be moved through the outdoor unit 10, the high pressure gas pipe 48, the low pressure gas pipe 49, and the third refrigerant pipe 18. The indoor unit mode control unit 30 may be provided such that a refrigerant may be moved while the indoor unit mode control unit 30 is connected to the flow path conversion apparatus 40 through the high pressure gas pipe 48, the low pressure gas pipe 49.

The indoor unit mode control unit 30 may be connected to the first indoor unit connecting pipes 21 a and 21 b, the second indoor unit connecting pipes 22 a and 22 b, and the third indoor unit connecting pipes 21 c and 21 c. The first indoor unit connecting pipes 21 a and 21 b, the second indoor unit connecting pipes 22 a and 22 b, and the third indoor unit connecting pipes 21 c and 21 c may be provided to connect the indoor unit mode control unit 30 and the each of the plurality of indoor units 20 so that a refrigerant may be moved. The first indoor unit connecting pipes 21 a and 21 b, the second indoor unit connecting pipes 22 a and 22 b, and the third indoor unit connecting pipes 21 c and 21 c may be provided such that the refrigerant in a gas state at a high pressure, the refrigerant in a gas state at a low pressure, and the refrigerant in a liquefied state may be moved according to the driving mode of the each indoor unit 20.

The flow path conversion apparatus 40 may be disposed in between the outdoor unit 10 and the indoor unit mode control unit 30. The flow path conversion apparatus 40 may change the flow path of the refrigerant being moved to the outdoor unit 10 or the indoor unit mode control unit 30. The flow path conversion apparatus 40, by changing the flow path of the flow path of the refrigerant being moved to the outdoor unit 10 or the indoor unit mode control unit 30, may be provided such that the each of the plurality of indoor units 20 provided at the heat pump 1 may be driven at a cooling mode or a heating mode.

The flow path conversion apparatus 40 may be connected to the first refrigerant pipe 16 and the second refrigerant pipe 17 that are connected to the outdoor unit 10. The flow path conversion apparatus 40 may be connected to the high pressure gas pipe 48 and the low pressure gas pipe 49 that are connected to the indoor unit mode control unit 30. The flow path conversion apparatus 40 may change the flow path of a refrigerant by selectively connecting some of the entirety of the first refrigerant pipe 16, the second refrigerant pipe 17, the high pressure gas pipe 48, and the low pressure gas pipe 49 according to the modes at which the indoor units 20 are driven.

The flow path conversion apparatus 40 may include the second flow path conversion apparatus 41, the high pressure gas pipe 48, and the low pressure gas pipe 49. The second flow path conversion apparatus 41 may be provided to be connected to the each of the first refrigerant pipe 16, the high pressure gas pipe 48, and the low pressure gas pipe 49. The second flow path conversion apparatus 41 may be structured as to connect some of the first refrigerant pipe 16, the high pressure gas pipe 48, and the low pressure gas pipe 49. The second flow path conversion apparatus 41 may connect the first refrigerant pipe 16 and the high pressure gas pipe 48 according to the driving modes of the indoor units, or may change the flow path of a refrigerant by connecting first refrigerant pipe 16 and the low pressure gas pipe 49. The second flow path conversion apparatus 41 may be provided in a form of a 4-way valve.

The high pressure gas pipe 48 may connect the second flow path conversion apparatus 41 and the indoor unit mode control unit 30. The high pressure gas pipe 48 may be provided as a flow path through which the refrigerant in a gas state at high pressure is moved from the second flow path conversion apparatus 41 to the indoor unit mode control unit 30.

The high pressure gas pipe 48 may be structured to be connected to one side of the second refrigerant pipe 17. Through the above, the high pressure gas pipe 48 may be provided in a form of a flow path through which the refrigerant in a gas state at a high pressure being moved through the second refrigerant pipe 17 is moved to the indoor unit mode control unit 30.

The low pressure gas pipe 49 may connect the second flow path conversion apparatus 41 and the indoor unit mode control unit 30. The low pressure gas pipe 49 may be provided as a flow path through which the refrigerant in a gas state at low pressure is moved from the indoor unit mode control unit 30 to the outdoor unit 10.

The flow path conversion apparatus 40 may further include a first valve 42, a second valve 43, and a connecting pipe 45.

The first valve 42 may be installed at the second refrigerant pipe 17 at an inside the flow path conversion apparatus 40. The first valve 42 may connect or close the second refrigerant pipe 17 and the high pressure pipe 48. The second refrigerant pipe 17 and the high pressure pipe 48 may be connected when the first valve 42 is open, and the connection between the second refrigerant pipe 17 and the high pressure pipe 48 may be closed when the first valve 42 is closed.

The connecting pipe 45 may connect the second refrigerant pipe 17 and the low pressure gas pipe 49. The connecting pipe 45 may be provided with the second valve 43 installed thereto. The second valve 43 may open/close the connecting pipe 45.

The first valve 42 and the second valve 43 along with the second flow path conversion valve 41 may change the flow path of the refrigerant being moved from the outdoor unit 10 to the indoor mode control unit 30. In addition, the first valve 42 and the second valve 43 along with the second flow path conversion valve 41 may change the flow path of the refrigerant being moved from the indoor unit mode control unit 30 to the outdoor unit 10.

Hereinafter, a circulation process of a refrigerant at the outdoor unit 10, the indoor units 20, the indoor unit mode control unit 30, and the flow path conversion apparatus 40 according to the driving modes of the indoor units at the already described heat pump 1 will be described.

FIG. 3 is a drawing showing a circulation of a refrigerant in a case when the plurality of indoor units of the heat pump illustrated on FIG. 2 is altogether at a cooling mode.

Referring FIG. 3, when the plurality of indoor units 20 altogether is driven at a cooling mode, the refrigerant in a liquefied state is moved from the outdoor unit 10 to the indoor unit mode control unit 30.

The refrigerant compressed in a gas state at high pressure at the compressor 11 may be moved to the third refrigerant pipe 18 from the first flow path conversion valve 15. The first flow path conversion valve 15 may connect the compressor 11 and the third refrigerant pipe 18. In addition, as the first valve 42 of the flow path conversion apparatus 40 closes the first refrigerant pipe 16, the refrigerant compressed in a gas state at high pressure may be prevented from being moved to the high pressure gas pipe 48 through the first refrigerant pipe 16. Through the above, the refrigerant compressed in a gas state at high pressure at the compressor 11 may be moved in a direction of the indoor unit mode control unit 30 only through the third refrigerant pipe 18.

The refrigerant in a gas state at high pressure being moved through the third refrigerant pipe 18 may be moved to the outdoor heat exchanger 12. The refrigerant in a gas state at high pressure may be condensed and liquefied at the outdoor heat exchanger 12. When the plurality of indoor units 20 altogether is driven at a cooling mode, the outdoor heat exchanger 12, while driven as a condenser, may liquefy the refrigerant in a gas state at high pressure by condensation. The liquefied refrigerant may be moved to the indoor unit mode control unit 30 through the third refrigerant pipe 18.

The liquefied refrigerant may be moved to the each of the indoor units 21, 22, and 23 from the indoor unit mode control unit 30. The liquefied refrigerant may be moved to the plurality of indoor units 21, 22, and 23 through the first indoor unit connecting pipe 21 a, the second indoor unit connecting pipe 22 a, and the third indoor unit connecting pipe 22 a. A cool air may be generated at the each of the plurality of indoor units 21, 22, and 23 as the liquefied refrigerant is evaporated. Through the above, the plurality of indoor units 21, 22, and 23 may be driven at a cooling mode. At the plurality of indoor units 21, 22, and 23 in the cooling mode, the liquefied refrigerant may be evaporated to the refrigerant in a gas state at low pressure. The refrigerant in a gas state at low pressure, which is evaporated at the plurality of indoor units 21, 22, and 23 may be moved to the indoor unit mode control unit 30 through the first indoor unit connecting pipe 21 b, the second indoor unit connecting pipe 22 b, and the third indoor unit connecting pipe 23 b that are connected to the indoor units 21, 22, and 23.

The refrigerant in a gas state at low pressure being moved to the indoor unit mode control unit 30 may be moved in a direction of the flow path conversion apparatus 40 through the low pressure gas pipe 49. As the second valve 43 is provided in a state of closing the connecting pipe 45, the refrigerant in a gas state at low pressure may be entirely moved to the second flow path conversion valve 41 through the low pressure gas pipe 49.

In a case when the plurality of indoor units 20 is altogether at a cooling mode, the second flow path conversion valve 41 may connect the refrigerant pipe 16 and the low pressure gas pipe 49. Through the above, the refrigerant in a gas state at low pressure may be moved to the outdoor unit 10 through the first refrigerant pipe 16 connected to the low pressure gas pipe 49.

The refrigerant in a gas state at low pressure may be moved to the first flow path conversion valve 15 through the first refrigerant pipe 16. The first flow path conversion valve 15 through may be structured as to connect the compressor 11 and the third refrigerant pipe 18, and connect the first refrigerant pipe 16 and the circulation pipe 19. Through the above, the refrigerant in a gas state at low pressure may be moved to the circulation pipe 19 connected to the first refrigerant pipe 16. The refrigerant in a gas state at low pressure may be moved to the compressor 11 along the circulation pipe 19 after passing through the accumulator 13.

FIG. 4 is a drawing showing a circulation of a refrigerant in a case when the plurality of indoor units of the heat pump illustrated on FIG. 2 is altogether at a heating mode.

Referring FIG. 4, when the plurality of indoor units 20 altogether is driven at a heating mode, the refrigerant in a gas state at high pressure is moved from the outdoor unit 10 to the indoor unit mode control unit 30.

The refrigerant compressed in a gas state at high pressure at the compressor 11 may be moved to the first refrigerant pipe 16 from the first flow path conversion valve 15. The first flow path conversion valve 15 may connect the compressor 11 and the first refrigerant pipe 16. The refrigerant compressed to a gas state at high pressure may be moved to the flow path conversion apparatus 40 through the first refrigerant pipe 16. The refrigerant compressed in a gas state at high pressure may be moved to the second flow path conversion valve 41 of the flow path conversion apparatus 40 through the first refrigerant pipe 16.

In a case when the plurality of indoor units 20 altogether is at a heating mode, the second flow path conversion valve 41 may connect the first refrigerant pipe 16 and the high pressure gas pipe 48. Through the above, the refrigerant compressed in a gas state at high pressure may be moved to the high pressure gas pipe 48 through the first refrigerant pipe 16. The refrigerant compressed to a gas state at high pressure may be moved to the indoor unit mode control unit 30 along the high pressure gas pipe 48.

The refrigerant compressed to a gas state at high pressure may be moved to the each of the indoor units 21, 22, and 23 from the indoor unit mode control unit 30. The refrigerant compressed to a gas state at high pressure may be moved to the plurality of indoor units 21, 22, and 23 through the first indoor unit connecting pipe 21 a, the second indoor unit connecting pipe 22 a, and the third indoor unit connecting pipe 22 a. At the plurality of indoor units 21, 22, and 23, the refrigerant compressed to a gas state at high pressure may be liquefied through condensation. The plurality of indoor units 21, 22, and 23 may be driven at a heating mode as heat is released after the refrigerant compressed to a gas state at high pressure is condensed.

The refrigerant liquefied at the plurality of indoor units 21, 22, and 23 may be moved to the indoor unit mode control unit 30 through the first indoor unit connecting pipe 21 b, the second indoor unit connecting pipe 22 b, and the third indoor unit connecting pipe 23 b that are connected to the indoor units 21, 22, and 23.

The liquefied refrigerant moved to the indoor unit mode control unit 30 may be moved to the outdoor unit 10 through the third refrigerant pipe 18. The liquefied refrigerant may be moved to the outdoor heat exchanger 12 along the third refrigerant pipe 18. The liquefied refrigerant is evaporated at the outdoor heat exchanger 12, and may be converted into a refrigerant in a gas state at low pressure. In a case when the plurality of indoor units 20 is altogether at a heating mode, the outdoor heat exchanger 12 may be driven as an evaporator. The refrigerant, which is in a gas state at low pressure, that is evaporated at the outdoor heat exchanger 12 may be moved to the first flow path conversion valve 15 through the third refrigerant pipe 18.

In a state when the plurality of indoor units 20 altogether is at a heating mode, the first flow path conversion valve 15 may be structured as to connect the compressor 11 and the first refrigerant pipe 16, and to connect the third refrigerant pipe 18 and the circulation pipe 19. Through the above, the refrigerant, which is in a gas state at low pressure, moved to the first flow path conversion valve 15 along the third refrigerant pipe 18 may be moved to the circulation pipe 19. The refrigerant in a gas state at low pressure may be moved to the compressor 11 after passing through the accumulator 13 along the circulation pipe 19.

FIG. 5 is a drawing showing a circulation of a refrigerant in a case when the plurality of indoor units of the heat pump illustrated on FIG. 2 is at a main cooling mode.

Referring to FIG. 5, in a case when the each of the plurality of indoor units 20 is driven at a heating mode and a cooling mode, and when the number of the indoor units 20 at the cooling mode is provided to be greater than the number of the indoor units 20 at the heating mode (hereinafter the case as such will be referred to as a main cooling mode), the refrigerant in a gas state at high pressure and the refrigerant in a liquid state may simultaneously be moved from the outdoor unit 10 to the indoor unit mode control unit 30.

The first flow path conversion valve 15 may connect the compressor 11 and the third refrigerant pipe 18. The refrigerant compressed to a gas state at high pressure at the compressor 11 may be moved from the first flow path conversion valve 15 to the third refrigerant pipe 18. Some of the refrigerant, which is in a gas state at high pressure, moved to the third refrigerant pipe 18 may be moved to the outdoor heat exchanger 12 along the third refrigerant pipe 18. In addition, the remaining of the refrigerant, which is in a gas state at high pressure, moved to the third refrigerant pipe 18, may be moved to the flow path conversion apparatus 40 along the second refrigerant pipe 17 connected to the third refrigerant pipe 18.

The refrigerant, which is in a gas state at high pressure, moved to the outdoor heat exchanger 12 may be condensed and liquefied. At this time, the outdoor heat exchanger 12 may be driven as a condenser to condense the refrigerant in a gas state at high pressure. The refrigerant liquefied at the outdoor heat exchanger 12 may be moved to the indoor unit mode control unit 30 along the third refrigerant pipe 18.

The refrigerant, which is in a gas state at high pressure, moved to the flow path conversion apparatus 40 along the second refrigerant pipe 17 is moved to the high pressure gas pipe 48. At this time, the first valve 42 of the flow path conversion apparatus 40 may be provided in an open state, and the second valve 43 may be provided in a closed state. Through the above, the refrigerant, which is in a gas state at high pressure, moved along the second refrigerant pipe 17 is moved to the high pressure has pipe 48 connected to the second refrigerant pipe 17, and may be moved to the indoor unit mode control unit 30 along the high pressure gas pipe 48.

The each of the refrigerant in a gas state at high pressure and the liquefied refrigerant, both of which are moved to the indoor unit mode control unit 30, may be moved differently with respect to each other, according to the modes of the indoor units 20. The refrigerant in a gas state at high pressure may be moved to the indoor unit 23, which is driven at a heating mode. The refrigerant in a gas state at high pressure may be moved to the indoor unit 23 through the third indoor unit connecting pipe 23 a, and may release heat after condensed at the indoor unit 23. The refrigerant condensed and liquefied at the indoor unit 23 may be moved to the indoor unit mode control unit 30 through the third indoor unit connecting pipe 23 b.

The liquefied refrigerant may be moved to the indoor units 21 and 22 driven at a cooling mode. The liquefied refrigerant may be moved to the each of the indoor units 21 and 22 through the first indoor unit connecting pipe 21 a and the second indoor unit connecting pipe 22 a. The liquefied refrigerant may release cool air after being evaporated at the indoor units 21 and 22. The refrigerant evaporated at the indoor units 21 and 22 may be moved to the indoor unit mode control unit 30 through the first indoor unit connecting pipe 21 b and the second indoor unit connecting pipe 22 b.

The refrigerant, which is in a gas state at low pressure, moved to the indoor unit mode control unit 30 may be moved to the flow path conversion apparatus 40 along the low pressure gas pipe 49. The second valve 43 of the flow path conversion apparatus 40 is provided in a closed state, so that the refrigerant in a gas state at low pressure may be entirely moved to the second flow path conversion valve 41 along the low pressure gas pipe 49. Differently from the above, the liquefied refrigerant moved to the indoor unit mode control unit 30 may be moved again to the indoor units 20.

The second flow path conversion valve 41 may be provided such that the first refrigerant pipe 16 and the low pressure gas pipe 49 are connected to each other. Through the above, the refrigerant, which is in a gas state at low pressure, moved through the low pressure gas pipe 49 may be moved to the first refrigerant pipe 16. The refrigerant in a gas state at low pressure may be moved to the outdoor unit 10 along the first refrigerant pipe 16. The refrigerant in a gas state at low pressure may be moved along the first refrigerant pipe 16 to the first flow path conversion valve 15 at an inside of the outdoor unit 10.

The first flow path conversion valve 15 may be provided such that the compressor 11 and the third refrigerant pipe 18 are connected to each other at a main cooling mode, and the first refrigerant pipe 16 and the circulation pipe 19 are connected to each other. Through the above, the refrigerant, which is in a gas state at low pressure, moved along the first refrigerant pipe 16 may be moved to the circulation pipe 19. The refrigerant in a gas state at low pressure may be moved to the compressor 11 along the circulation pipe 19 after passing through the accumulator 13.

FIG. 6 is a drawing showing a circulation of a refrigerant in a case when the plurality of indoor units of the heat pump illustrated on FIG. 2 is at a main heating mode.

Referring to FIG. 6, in a case when the each of the plurality of indoor units 20 is driven at a heating mode and a cooling mode, and when the number of the indoor units 20 at the cooling mode is provided to be less than the number of the indoor units 20 at the heating mode (hereinafter the case as such will be referred to as a main heating mode), the refrigerant in a gas state at high pressure may be moved from the outdoor unit 10 to the indoor unit mode control unit 30.

At the main heating mode, the first flow path conversion valve 15 may connect the compressor 11 and the first refrigerant pipe 16. The refrigerant compressed to a gas state at high pressure at the compressor 11 may be moved from the first flow path conversion valve 15 to the first refrigerant pipe 16. The refrigerant in a gas state at high pressure may be moved along the first refrigerant pipe 16 to the flow path conversion apparatus 40. The refrigerant in a gas state at high pressure may be moved along the first refrigerant pipe 16 to the second flow path conversion valve 41 of the flow path conversion apparatus 40.

At the main heating mode, the second flow path conversion valve 41 may be provided such that the first refrigerant pipe 16 and the high pressure gas pipe 48 are connected to each other. The refrigerant, which is in a gas state at high pressure, moved through the first refrigerant pipe 16 may be moved to the high pressure gas pipe 48 connected to the second flow path conversion valve 41. The refrigerant in a gas state at high pressure may be moved along the high pressure gas pipe 48 to the indoor unit mode control unit 30.

The refrigerant, which is in a gas state at high pressure, moved to the indoor unit mode control unit 30 may be moved differently according to the mode of the each indoor unit 20. The refrigerant in a gas state at high pressure may be moved to the indoor units 21 and 22 that are driven at a heating mode. The refrigerant in a gas state at high pressure may be moved to the indoor units 21 and 22 through the first indoor unit connecting pipe 21 a and the second indoor unit connecting pipe 22 a, respectively. The refrigerant in a gas state at high pressure may be condensed and then liquefied at the indoor units 21 and 22. The liquefied refrigerant may be moved to the indoor unit mode control unit 30 through the first indoor unit connecting pipe 21 b and the second indoor unit connecting pipe 22 b.

The liquefied refrigerant moved to the indoor unit mode control unit 30 may be moved through the third indoor unit connecting pipe 23 a to the indoor unit 23 at a cooling mode. Cool air may be released at the indoor unit 23 we the liquefied refrigerant is evaporated. The liquefied refrigerant may be changed to a gas state at low pressure as the liquefied refrigerant is evaporated at the indoor unit 23. The refrigerant in a gas state at low pressure may be moved through the third indoor unit connecting pipe 23 b to the indoor unit mode control unit 30.

The refrigerant in a gas state at low pressure and the liquefied refrigerant, both of which are moved to the indoor unit mode control unit 30, may be moved through the low pressure gas pipe 49 and the third refrigerant pipe 18, respectively, in a direction toward the outdoor unit 10.

The refrigerant in a gas state at low pressure may be moved through the low pressure gas pipe 49 to the flow path conversion apparatus 40. At the main heating mode, the first valve 42 may be provided to be closed and the second valve 43 may be provided to be open. Accordingly, the refrigerant in a gas state at low pressure may sequentially be moved to the low pressure gas pipe 49, the connecting pipe 45, and the second refrigerant pipe 17. The refrigerant in a gas state at low pressure may be moved through the second refrigerant pipe 17 to the outdoor unit 10. The refrigerant in a gas state at low pressure may be moved through the second refrigerant pipe 17 to the first flow path conversion valve 15 of the outdoor unit 10.

The liquefied refrigerant may be moved through the third refrigerant pipe 18 to the outdoor unit 10. The liquefied refrigerant may be moved through the third refrigerant pipe 18 to the outdoor heat exchanger 12 of the outdoor unit 10. The refrigerant liquefied at the outdoor heat exchanger 12 may be evaporated and then changed to a refrigerant in a gas state at low pressure. At the main heating mode, the outdoor heat exchanger 12 may be driven as an evaporator. The refrigerant, which is in a gas state at low pressure, generated at the outdoor heat exchanger 12 may be moved through the third refrigerant pipe 18 to the first flow path conversion valve 15. The refrigerant, which is in a gas state at low pressure, moved along the second refrigerant pipe 17, and the refrigerant, which is in a gas state at low pressure, moved through the third refrigerant pipe 18 altogether may be moved to the first flow path conversion valve 15.

At the main heating mode, the first flow path conversion valve 15 may be provided such that the third refrigerant pipe 18 and the circulation pipe 19 are connected to each other. Through the above, the refrigerant, which is in a gas state at low pressure, moved through the third refrigerant pipe 18 may be moved from the first flow path conversion valve 15 to the circulation pipe 19. The refrigerant in a gas state at low pressure may be moved after passing through the accumulator 13 along the circulation pipe 19 to the compressor 11.

Hereinafter, the motions of the outdoor unit 10 and the flow path conversion apparatus 40 according to time in a case when the heat pump 1 is driven at cooling, heating, main cooling, and main heating modes will be described in detail.

FIG. 7 is a drawing showing the motions of the outdoor unit and the flow path conversion apparatus according to time in a case when the heat pump of FIG. 2 is driven at a cooling mode or at a main cooling mode in a halted state.

Referring to FIG. 7, when the heat pump 1 is driven at a cooling mode in a halted state, the compressor 11 may be driven. At this time, the first flow path conversion valve 15 may connect the compressor 11 and the third refrigerant pipe 18, and may maintain the first refrigerant pipe 16 and the circulation pipe 19 in a connected state. The second flow path conversion valve 41 may be provided that the first refrigerant pipe 16 and the low pressure gas pipe 49 are maintained in a connected state. The first valve 42 and the second valve 43 may be maintained in a closed state.

In addition, when the heat pump 1 is driven at a main cooling mode in a halted state, the compressor 11 may be driven, the first flow path conversion valve 15, the second flow path conversion valve 41, and the second valve 43 are maintained in a closed state, and the first valve 42 may be open according to the signal of some of the indoor units 20 that are driven at a heating mode.

FIG. 8 is a drawing showing the motions of the outdoor unit and the flow path conversion apparatus according to time in a case when the heat pump of FIG. 2 is driven at a heating mode or at a main heating mode in a halted state.

Referring to FIG. 8, when the heat pump 1 is driven at a heating mode in a halted state, the compressor 11 may be driven after the second valve 43 is open first. Along with the driving of the compressor 11, the first flow path conversion valve 15 may be switched in a state that the compressor 11 and the first refrigerant pipe 16 are connected to each other and the third refrigerant pipe 18 are the circulation pipe 19 are connected to each other. In addition, the second flow path conversion valve 41 may be switched along with the driving of the compressor 11 in a state that the first refrigerant pipe 16 and the high pressure gas pipe 48 are connected to each other.

After the compressor 11 is driven, the second valve 43 may be changed to a closed state after maintaining an open state for a certain period of time. As the above, prior to the driving of the compressor 11, the second valve 43, if maintained in an open state for a certain period of time, may easily form the difference in pressure of the second flow path conversion valve 41, and accordingly, the reliability of the switching of the second flow path conversion valve 41 may be improved.

In addition, when the heat pump 1 is driven at the main heating mode in a halted state, the compressor 11 may be driven after the second valve 43 is open first. Along with the driving of the compressor 11, the first flow path conversion valve 15 may be switched in a state that the compressor 11 and the first refrigerant pipe 16 are connected to each other and the third refrigerant pipe 18 and the circulation pipe 19 are connected to each other. In addition, the second flow path conversion valve 41 may be switched along with the driving of the compressor 11 in a state that the first refrigerant pipe 16 and the high pressure gas pipe 48 are connected to each other. The second valve 43 may be open according to the signal of some of the indoor units 20 that are driven at a cooling mode.

FIG. 9 is a drawing showing the motions of the outdoor unit and the flow path conversion apparatus according to time in a case when the heat pump of FIG. 2 is driven at a heating mode or a main heating mode during a cooling mode or a main cooling mode.

Referring to FIG. 9, when the heat pump 1 is driven at a heating mode or at a main heating mode during a cooling mode or a main cooling mode, the driving frequency of the compressor 11 in a driving state is decreased, and at the same time, the first valve 42 may be open. After the first valve 42 is open, the second flow path conversion valve 41 may be switched in a state that the first refrigerant pipe 16 and the high pressure gas pipe 48 are connected to each other while in a state that the first refrigerant pope 16 and the low pressure gas pipe 49 are connected to each other.

After the second flow path conversion valve 41 is switched, the first flow path conversion valve 15 may be switched in a state the compressor 11 and the first refrigerant pipe 16 are connected to each other and the third refrigerant pipe 18 and the circulation pipe 19 are connected to each other while in a state that the compressor 11 and the third refrigerant pipe 18 are connected to each other and the first refrigerant pipe 16 and the circulation pipe 19 are connected to each other.

The second valve 43 may be open as well at the same time when the first flow path conversion valve 15 is switched. After the first flow path conversion valve 15 is switched and the second valve 43 is open, the first valve 42 is closed and at the same time the rotational frequency of the compressor 11 may be increased. As a result of the above-described driving, the heat pump 1 may be driven at a heating mode or at a main heating mode during a cooling mode or a main cooling mode, and as the difference in pressure of the second flow path conversion valve 41 may easily be formed, the reliability of the switching of the second flow path conversion valve 41 may be improved.

FIG. 10 is a drawing showing the motions of the outdoor unit and the flow path conversion apparatus according to time in a case when the heat pump of FIG. 2 is driven at a cooling mode or a at main cooling mode during a heating mode or a main heating mode.

Referring to FIG. 10, when the heat pump 1 is driven at a cooling mode or at a main cooling mode during a heating mode or a main heating mode, the driving frequency of the compressor 11 in a driving state may consistently be decreased. After the driving frequency of the compressor 11 in a driving state is decreased, the second valve 43 in an open state may be closed.

After the second valve 43 is closed, the first flow path conversion valve 15 may be switched in a state that the compressor 11 and the third refrigerant pipe 18 are connected and the first refrigerant pipe 16 and the circulation pipe 19 are connected to each other, while in a state that the third refrigerant pope 18 and the circulation pipe 19 are connected to each other.

The second flow path conversion valve 41 may be switched at the same time when the first flow path conversion valve 15 is switched. The second flow path conversion valve 41 may be switched in a state that the first refrigerant pipe 16 and the low pressure gas pipe 49 are connected to each other while in a state that the first refrigerant pipe 16 and the high pressure gas pipe 48 are connected to each other.

After the first flow path conversion valve 15 and the second flow path conversion valve 41 are switched, the driving frequency of the compressor 11 may consistently be increased, and at the same time, the first valve 42 in a closed state may be open. As a result of the above-described driving, the heat pump 1 may be driven at a cooling mode or at a main cooling mode during a heating mode or a main heating mode, and as the difference in pressure of the second flow path conversion valve 41 may easily be formed, the reliability of the switching of the second flow path conversion valve 41 may be improved.

Although a few embodiments of the present disclosure have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the disclosure, the scope of which is defined in the claims and their equivalents. 

What is claimed is:
 1. A heat pump, comprising: an outdoor unit having a compressor and an outdoor heat exchanger; a plurality of indoor units, each of the indoor units configured to be driven at one of a cooling mode and a heating mode; an indoor unit mode control unit configured to control each of the plurality of indoor units to be driven at one of the cooling mode and the heating mode; and a flow path conversion apparatus connected to the outdoor unit through a first refrigerant pipe and a second refrigerant pipe, connected to the indoor unit mode control unit through a high pressure gas pipe and a low pressure gas pipe, and configured to change a flow path of a refrigerant by selectively connecting at least one of the first refrigerant pipe and the second refrigerant pipe to the high pressure gas pipe and the low pressure gas pipe according to a mode at which the indoor units are driven.
 2. The heat pump of claim 1, wherein the outdoor unit further comprises a first flow path conversion valve connected to the compressor, the first refrigerant pipe, and the second refrigerant pipe, and configured to connect the compressor to one of the first refrigerant pipe and the second refrigerant pipe.
 3. The heat pump of claim 2, wherein the outdoor unit further comprises: an accumulator connected to the compressor; and a circulation pipe to sequentially connect the first flow path conversion valve, the accumulator, and the compressor.
 4. The heat pump of claim 2, further comprising: a third refrigerant pipe to sequentially connect the second refrigerant pipe, the outdoor heat exchanger, and the indoor unit mode control unit.
 5. The heat pump of claim 3, wherein the flow path conversion apparatus comprises: a second flow path conversion valve connected to each of the first refrigerant pipe, the high pressure gas pipe, and the low pressure gas pipe, and configured to connect the first refrigerant pipe to one of the high pressure gas pipe and the low pressure gas pipe; a first valve installed at the second refrigerant pipe configured to connect the first flow path conversion valve and the high pressure gas pipe; and a second valve installed at a connecting pipe connecting the second refrigerant pipe and the low pressure gas pipe.
 6. The heat pump of claim 5, wherein the connecting pipe is connected in between the first valve and the first flow path conversion valve at the second refrigerant pipe.
 7. The heat pump of claim 6, wherein the flow path conversion apparatus further comprises a control apparatus to control the first flow path conversion valve, the first valve, and the second valve, and when the plurality of indoor units is altogether driven at the cooling mode, the control apparatus controls the first flow path conversion valve to connect the compressor and the second refrigerant pipe and to connect the circulation pipe to the first refrigerant pipe, and controls the second flow path conversion valve to connect the first refrigerant pipe and the low pressure gas pipe.
 8. The heat pump of claim 7, wherein the control apparatus, when the plurality of indoor units is driven at the cooling mode altogether, controls both the first valve and the second valve to be closed.
 9. The heat pump of claim 6, wherein the flow path conversion apparatus further comprises a control apparatus configured to control the first flow path conversion valve, the first valve, and the second valve, and when the plurality of indoor units is altogether driven at the heating mode, the control apparatus controls the first flow path conversion valve to connect the compressor and the first refrigerant pipe and to connect the circulation pipe to the second refrigerant pipe, and the second flow path conversion valve to connect the first refrigerant pipe and the high pressure gas pipe.
 10. The heat pump of claim 9, wherein the control apparatus, when the plurality of indoor units is driven at the heating mode altogether, controls both the first valve and the second valve to be closed.
 11. The heat pump of claim 6, wherein the flow path conversion apparatus further comprises a control apparatus configured to control the first flow path conversion valve, the first valve, and the second valve, and when a number of the indoor units driven at the cooling mode is greater than a number of the indoor units driven at the heating mode, the control apparatus controls the first flow path conversion valve to connect the compressor and the second refrigerant pipe and to connect the circulation pipe to the first refrigerant pipe, and the second flow path conversion valve to connect the first refrigerant pipe and the low pressure gas pipe.
 12. The heat pump of claim 11, wherein the control apparatus, when the number of the indoor units driven at the cooling mode is greater than the number of the indoor units driven at the heating mode, controls the first valve to be open and the second valve to be closed.
 13. The heat pump of claim 6, wherein the flow path conversion apparatus further comprises a control apparatus configured to control the first flow path conversion valve, the first valve, and the second valve, and when a number of the indoor units driven at the heating mode is greater than a number of the indoor units driven at the cooling mode, the control apparatus controls the first flow path conversion valve to connect the compressor and the first refrigerant pipe and to connect the circulation pipe to the second refrigerant pipe, and the second flow path conversion valve to connect the first refrigerant pipe and the high pressure gas pipe.
 14. The heat pump of claim 13, wherein when the number of the indoor units driven at the heating mode is greater than the number of the indoor units driven at the cooling mode, the control apparatus controls the first valve to be closed and the second valve to be open.
 15. The heat pump of claim 6, wherein the first flow path conversion valve and the second flow path conversion valve are provided in a form of a 4-way valve. 